Calculating device.



2 Sheets-Sheet l.

Patented 1an. I4, |902.

A. L BUTT.

CALCULATING DEViCE.

(Application filed July 20, 1901.)

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(No Model.)

Patented Jan. I4, |902.

A. L. BUTT. CALCULATING DEVCE.

(Application led July 20, 1901.)

2 Sheets-Sheet 2.

(No Model.)

NiTnD STATES PATENT FFICE.

ALBERT LEONIDAS BUTT, OF RUSSELLVILLE, KETUCKY.

cALcULATlNG DEVICE.

SPECIFICATION forming part of Letters Patent No. 690,924, dated January 14, 1902.

Application tiled July, 20, 1901. Serial No. 69,090. (No model.)

To @ZZ whom t may concern;

Be it known that I, ALBERT LEONIDAs BUTT, a citizen of the United States, residing at Russellville, in the county of Logan and State of Kentucky, have invented a new and useful Calculating Device, of which the following is a speciiication.

Among bankers, accountants, and persons engaged in similar work one of the most tedious tasks, which also employs a great amount of time, is the ascertainment of interest due on amounts for short periods of time, such as are reckoned by days.

The present invention relates to mechanical calculators designed to obviate the necessity of figuring these rather involved problems by providing means whereby the interest on any ordinary amount for a number of days may be readily ascertained.

A further object resides in means for mechanically calculating suchinterest at different rates of per cent. f

The preferred embodiment of the invention is illustrated in the accompanying drawings,

and the construction and operation thereof is fully described in the following specification.

The invention, however, is not to be limited to the particular embodiment shown and described, but is open to such changes and modiications as may fall within the scope of the claims.

In the drawings, Figure lis a top plan view of the calculator. Fig. 2 is a vertical longitudinal sectional view through the same. Fig. 3 is a vertical transverseV section. Fig. 4c is an end elevation. Fig. 5 is a detail perspective view of the finder-plate and the operating mechanism therefor. Fig. 6 is a detail View of the spring-dog and the controlling device therefor. Fig. 7 is a detail View of a modified form of holding device.

Similar reference-numerals designate similar parts throughout the several figures of the drawings. o

In carrying out the present invention a casing 10 is provided, preferably rectangular in form and having a transparent top 11, preferably .of glass, said top being held in place by the straps 12 4or other suitable means. Located directly beneath the transparent top is a plate 12a, said plate havingl a longitudinally-disposed slot 13 therein, which slot is preferably located in the central portion of the plate.

Located within the casing is a movable element carrying a table of interest calculations. This element is shown inthe form of a cylinder 14, the face' of which is divided into small squares 15, said squares being arranged in longitudinal rows, each longitudinal row having located therein the interest on certain amounts for a certain number of days. As is shown in Fig..l, the interest on amounts varying from one dollar to ten thousand dollars for nineteen days is displayed, said interest being at eight per cent. In the practical embodiment of the invention for. certain purposes a plurality of rows are employed for each day, each row being at a different rate per cent., three being shown--sX, eight, and ten per cent.v

The cylinder 14: is mounted within the casing upon a shaft 16, one end of said shaft being set in a bearing 17 on the inner face of the casing,`while the outer end projects through the opposite end of the casing and has an operating-handle in the form of a milled wheel 18V. The end of the cylinder opposite the handle is provided with a ratchet-disk 19, normally engaged by a pivoted dog 20, which is yieldingly held in such position by a spring 2l, secured inside the casing. In order to throw the dog out of engagement, a vertical releasing-stem 22 bears at its lower end upon said dog and has its upper end projecting above the casing and provided with a pushbutton 23. In Fig. 7 a slightly-modified form v of holding device is employed, the dog being in the form of a springhaving a tooth that engages between the .teeth of the disk and rides over the same when the cylinder is turned.

Located upon the upper faces of the plate 12 and beneath the glass top 11 is an-indeX 24, said index comprising a plurality of pointers 25, having the amounts indicated thereon and having sharpened ends that are located at the edge of the sight-opening directly above the squares in which the respective amounts of interest are displayed. At one end of the sight-opening there is arranged-therates of interest which correspond to the three rows simultaneously located beneath said sightopening.

IOO

In order to avoid confusion between the different rates of interest for a certain day, a finder-plate 26 is slidably mounted beneath the plate 12 and has a longitudinal slot 27 largeenough to display but one row at a time, said finder-plate being movable, so that any one of the three rows may be shown. This plate is connected by links 28 to crank-arms 29, secured to a rock-shaft 30, arranged longitudinally within the upper end of the casing and having an exposed end, provided with a milled operating-head 31. By oscillating the head it will thus be seen that the plate may be moved so as to expose the row of iigures alined with either the six, eight, or ten per cent. marks.

The operation of the device will be readily understood. Assuming, for instance, that it is desired to tind the interest on ten thousand dollars at eight per cent. and for nineteen days, the milled head 31 is rotated so as to move the finder-plate until the slot thereof is in line with the eight-per-cent. mark at the end of the sight-opening. The stem 22 is then depressed, so as to move the holdingdog out of engagement with the ratchet-disk, whereupon the cylinder may be rotated by means of the operating-wheel 18 until the number 19 appears at the index-pointer of Days, whereupon the interest on ten thousand dollars will appear ai' the 10,000 pointer, all of which is clearly shown in Fig. 1. If it is desired to iind the amount at six per cent., it is only necessary to slide the {inderplate along until the six-per-cent. row is uncovered. By this means it will be seen that an exceedingly-simple structure is provided which will be readily understood and affords means for quickly calculating the interest for a short period wit-hout the necessity of involved mathematical calculations.

To further heighten the usefulness of the 1nachine,there maybeemployedin connection therewith simple means for calculating the number of days in a determinate period, so that after said number is found the device may be used in calculating the interest on an amount for that time. This means consists in a plurality of circular fields printed or otherwise made upon the exposed face of the plate 12, one field being employed for each month of the year. As shown in Fig. l, six of these iields are preferably located upon one side ot' the said opening and six upon the other, each iield comprising a central circular space 32, from which radiatelines 33, that divide the field into twelve equal sections, these sections being consecutively numbered and having the numbers located in a rim 34, surroundingthe field. Each division is separated into two sections bya circular line 35, and in the outer sections are placed the names of the months, arranged consecutively, while the inner sections have the number of days from the month named in the central space to the month mentioned in the outer section plus three days ofgrace and includingthestarting day. For instance, in the first iield, having January in the center to I 1`ebruary,77 is thirty-one days plus the three days of grace, and including the first day equals thirty-five days. Assuming, therefore, that it is desired to iind the number of days in four months from July 4, it is only necessary to examine the field having July in the center and find the number 4 mark on the rim thereof. It will be seen that this mark indicates that November is the fourth month and that it is one hundred and twenty-seven days from said 4th of July to the 4th of November, including the necessary three days of grace and the day of starting-namely, the 4th of July. Hence the last day of grace will be November 4 plus three, or November 7. It will be readily understood by those skilled in the art that this day-calculator is of the greatest importance in connection with the interest-calculating device, as it often happens that the time will be given in months, while the interest must be calculated in days. This affords ready means for finding the number of days whereupon the interest may be calculated in the manner above described.

From the foregoing it is thought that the construction, operation, and many advantages of the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that Various changes in the size, shape, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a calculator, the combination with a casing having a sight-opening, of a cylinder rotatably mounted within the casing and carrying a table of interest calculations, said calculations being` successively displayed through the sight-opening upon the movement of the cylinder, an index for said table located adjacent to the sight-opening, an operating-handle located on the exterior of the casing and connected to one end of the cylinder, and a holding device located within the casing and arranged on the opposite end of the cylinder to the handle to hold said cylinder against movement.

2. In a calculator, the combination with a casinghavinga sight-opening, ofa cylinder rotatably mounted within the casing and carrying a table of interest calculations, said calculations being successively displayed throughl the sight-opening upon the movement of the cylinder, an index for the table located adjacent to the sight-opening, an operating-handle arranged on the exterior of the casing and connected to one end of the cylinder,a ratchetdisk secured to the other end of the cylinder, and a spring-pressed dog engaging the disk to hold the cylinder against movement.

3. In a calculator, the combination with a casing having a sight-opening,of a cylinder rotatably mounted Within the casing and hav' ing a table of interest calculations, an index for said table located adjacent to the sightopening, means for rotating the cylinder, a ratchet-'disk secured to the cylinder, a springpressed dog engaging the disk to hold the element against movement, and a controllingstem `bearing against the dog to move the same out of engagement With the disk.

4. In a calculator, the combination with a closed casing having a sight-opening through one of its Walls, of a movable element mounted Within the casing and carrying'a table of interest calculations comprising independent sets, a plurality of which are simultaneously displayed through the sight-opening, an index located upon the casing contiguous to the sight-opening, and a lnder-plate movable across the sight-opening and provided With an opening of smaller size than the said sightopening, the openingin said finder-plate beingof sufficient size to expose a single set of interest calculations.

5. In a calculator, the combination With a casing having a sight-opening, of a movable element mounted Within the' casing and earryingatable of interest calculations, an index located contiguous to the sight-opening, a

finder-plate movable across the said openingv and provided With an opening of smaller size than said sightfopeniug, and means for moving the finder-plate.

6. In a calculator, the combination with a casing having a sight-opening, of a movable element mounted Within the casing and carrying a table of interest calculations, an index located contiguous to the sight-opening, a linder-plate movable across the said opening and provided With an opening of smaller size than said sight-opening, a rockshaft having an exposed handle, and a connection between the shaft and lnder-plate.

'7. In a calculator, the combination with a casing having a sight-opening,of a cylinder rotatably mounted Within the casing and carrying a table of interest calculations, an index located contiguous to the sightopening, a finder-plate slidably' mounted across the said opening and provided with an opening of smaller size than said sight-opening, a rockshaftjournaled upon the casing and having an exposed handle and a pair of crank-arms, and links connecting the crank-arms to the linderplate.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two Witnesses.

ALBERT LEONIDAS BUTT.

Witnesses:

TOM RHEA, A.. S. DAVIS. 

